1. Field of the Invention
The present invention relates to an intra-tube traveling apparatus of an intra-tube test apparatus such as an endoscope, which tests the interior of, e.g., an industrial pipe path or of an organic canal while it is self-driven to travel in the pipe path.
2. Description of the Related Art
As an intra-tube traveling apparatus of this type, an apparatus having an arrangement disclosed in, e.g., Published Unexamined Japanese Patent Application No. 63-91555 has been developed. A moving unit of this intra-tube traveling apparatus has a substantially tubular elastic contraction member which is radially expanded/deformed and axially generates a contracting force upon reception of a pressurized fluid. Attaching members are respectively arranged on the two ends of this elastic contraction member. A spring member is arranged between the attaching members so as to generate a biasing force in a direction opposite to the axial contraction/deformation direction of the elastic contraction member. In addition, balloon-like lock members which are radially expanded/deformed upon reception of a pressurized fluid are respectively attached to the attaching members.
When the intra-tube traveling apparatus is to be used, the moving unit of the intra-tube traveling apparatus is inserted in a pipe path to be tested. In this state, a pressurized fluid is supplied/discharged to/from the elastic contraction member in accordance with alternate supply and discharge of the pressurized fluid to/from the respective lock members in the following manner, thus performing a forward or backward movement operation of the moving unit.
More specifically, when the moving unit of the intra-tube traveling apparatus is to be moved forward, the pressurized fluid is supplied to the lock member on the front side first to expand/deform it in the radial direction, thus urging the lock member against the inner surface of a pipe path in which the moving unit is inserted and locking it thereto.
While this state is held, the pressurized fluid is supplied to the elastic contraction member to expand/deform it in the radial direction and to simultaneously contract it in the axial direction, thereby moving the attaching member on the rear side forward upon expansion/deformation of the elastic contraction member.
Subsequently, while the lock member on the front side and the elastic contraction member are kept radially expanded/deformed, the pressurized fluid is supplied to the lock member on the rear side to expand/deform it in the radial direction, thus urging it against the inner surface of the pipe path in which the moving unit is inserted and locking it thereto.
In this state, the pressurized fluid is discharged from the lock member on the front side and from the elastic contraction member to elastically restore the elastic contraction member to the original shape with the aid of the biasing force of the spring member, thereby moving the attaching member on the front side forward.
By repeating this series of operations, a forward movement operation of the moving unit of the intra-tube traveling apparatus is performed.
When the moving unit of the intra-tube traveling apparatus is to be moved backward, the pressurized fluid is supplied to the lock member on the rear side first to expand/deform it in the radial direction, thus urging it against the inner surface of the pipe path in which the moving unit is inserted and locking it thereto.
Subsequently, the pressurized fluid is supplied to the elastic contraction member to expand/deform it in the radial direction. Upon expansion/deformation of the elastic contraction member, the attaching member on the front side is moved backward.
In this state, the pressurized fluid is supplied to the lock member on the front side to expand/deform it in the radial direction, thus urging it against the inner surface of the pipe path in which the moving unit is inserted and locking it thereto.
After this operation, the pressurized fluid is discharged from the lock member on the rear side and from the elastic contraction member to elastically restore the elastic contraction member to the original shape with the aid of the biasing force of the spring member, thus moving the attaching member on the rear side backward.
By repeating this series of operations, a backward movement operation of the moving unit of the intra-tube traveling apparatus is performed.
In the above-described conventional arrangement, a series of operations for forward or backward movement of the moving unit is performed by sequentially supplying/ discharging a pressurized fluid to the respective lock members and the elastic contraction member of the moving unit of the intra-tube traveling apparatus at proper timings. However, the moving unit cannot be stopped at an arbitrary position in the process of forward or backward movement of the moving unit. When a stop operation of the moving unit is performed in the process of forward or backward movement of the moving unit in order to perform detailed observation of, e.g., a corroded portion of a pipe wall or a similar operation, the pressurized fluid may be unintentionally discharged from the lock members to release the lock.
Especially, in a vertical pipe path, the apparatus may drop. Therefore, observation must be performed without stopping the moving unit.